Electric receptacle



ELECTRIC RECEPTACLE Filed May 22, 1936 IVA/entor:r L-eOhar'd VV. Cook.

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is Attorrweg Patented Feb. 2s, 1939- UNITED STATES ELECTRIC RECEPTACLE Leonard W. Cook, Bridgeport, Conn., assgnor to General Electric Company, a. corporation of New York Application May 22, 1936, serial No. 81,205

4 claims.

My invention relates Vto improvements Vin electrical receptacles or sockets. More particularly, my invention relates to a socket receptacle for vacuum tubes.

An object of my invention is to provide animproved receptacle or socket particularly for radio vacuum tubes which insures efficient contact with each and every prong of a plug-in device and to thereafter maintain such efficient contact.

Another object of my invention is to provide an improved receptacle, comprising relatively few different parts, which can be readily mounted on a panel which will have an insulated front and which will be cheap to manufacture.

A further object of my invention is to provide a receptacle which co-operates with a vacuum tube or the like, such lthat any given prong of the tube is always received by a predetermined prong receiving contact structure.

A furtherobject of my invention is to provide a novel prong receiving contact structure formed from a single piece ofL metal.

My invention will be'more fully set forth in the following description referring to the accompanying drawing, andthe features of novelty which characterize my invention will be pointed out with particularity in the claims appended to and forming a part of this specification.

In the drawing, which illustrates one embodiment of my invention, Fig. 1 is a side view of the socket receptacle, showing the parts thereof in assembled relationship, the receptacle supporting structure and a radio vacuum tube plugged into the receptac1e;.Fig. 2 is a bottom 5 view of the socket receptacle showing the prong receiving contact structures depending from the bottom thereof; Fig. 3 is a partial section taken along line 3--3 of Fig. 2, showing one of the prong receiving contact structures secured `in place; Fig. 4 is a partial'section taken along the line 4-4 of Fig.- 3; Fig. 5 is a perspective view of one of the contact structures; and Fig. 6 is a perspective view of the means which fastens the contact structure in place inthe receptacle.

Referring to the' drawing, particularly Fig. 1, there is shown my socket receptacle, designated generally at I0, in assembled relationship, in combination with ,a suitable supporting structure Il, and a radio vacuum tube I2 of the metal tube type, plugged into the socket receptacle. In Figs. 2 and 3, it will be observed that the socket receptacle Ill includes a plate of insulating material I3 provided with a guide passage I4 and a plurality of prong receiving passages I5 therein. Preferably, guide passage I4 is centrally disposed in plate I3 and prong receiving passages I5 are symmetrically disposed about guide passage I4. Of course the disposition of prong receiving passages l5 depends upon the disposition of the co-operating prongs distributed about the base of vacuum tube I2, as the passages must receive the tube prongs. i

The guide passage I4 is vprovided with a suitable groove I6 in at least one portion thereof which, together with the guide passage allows the vacuum tube I2 to be inserted into the socket receptacle only when the tube is in a predetermined position with respect to the socket receptacle. This relationship between the vacuum tube and the socket receptacle is effected by the co-operation between guide passages I4` and its groove I6 in the socket-receptacle plate I3 and a central guide member provided with a key (not shown) on the vacuum tube I2. The keyed central guide member on the vacuum tube is made somewhat longer than the prongs thereabout for a purpose hereinafter described.

Thus, it is apparent, due to co-operation above described, that any given prong on vacuum tube I2 is always received by a predetermined prong receiving passage I5 in the plate of insulating material I3.

A plurality of independent contact structures I6 depend from plate I3 on the underside thereof in alignment with prong receiving passages I5 so as to receive the prongs disposed about the base of vacuum tube I2 when the tube is inserted into the socket receptacle. These contact structures firmly grip the prongs of the vacuum tube and securely hold the tube in place in addition to serving as electrical connections for the elements ,within the vacuum tube.

It is impossible for the prongs on the vacuum tube to make contact with the contact structures unless the tube is in proper relation with respect to the socket receptacle, as the tube prongs are shorter than the keyed central guide member on the tube.

Referring to Figs. 3 and 5, the contact structure I6 comprises a contact portion Il for receiving the prong of a vacuum tube, a body portion I8 and a lead-connection portion I9, formed from a single piece of metal. Preferably, the structure is struck from a piece of'metal of high conductivity, such as copper or brass, and subsequently formed into the desired shape, thus producing a rugged integral structure. The struck blank comprises complementary halves which are folded together along fold 2l), during the forming process, to produce the contact structure shown in Fig. 5.

The contact portion I1 of the structure'is preferably formed as a hyperboloid of revolution so as to have a throat portion of less cross-sectional area than either open end of the hyperboloid.

That is, the diameter of the throat of the 'contact isless than the diameters of the open ends of the contact. Furthermore, the diameter of the upper open end of the contact is greater than i the diameter of the prong on the vacuum tube,

which the contact will receive, while the diameter of the throat of the contact is slightly smaller than the diameter of the prong. Thus, it will be apparent .that when a prong' is inserted through prong receiving passage I5, in insulating plate I3, into'the contact portion I1 of contact structure I6 that the warped surface of thel contact portion between the upper open end and the throat of the same will guide the prong'easily into place and cause the prong to spread or strain the contact out of shape. The contact is tails' may be tinned and conveniently soldered to a plurality of connecting wires.

As hereinbefore pointed out, each contact structure I6' is independently secured to plate I3. This securing means includes a U-shaped steel clip 23shown in Fig. 6, the U of which embraces the body portion I8 of contact structure I6' and firmly holds the structure to the underside of plate I3. The ends 24 of clip 23 pass through .an aperture 25 inplate I3 and are bent over to secure the contact structure I6' in place as is shown in Fig. 4. Bosses 26 are formed in ,clip 23 just at the point Where the ends 24 of the clip are bent over in order to prevent the contact structure from rocking in the U of the clip.

Tab 22 on the body portion of the contact structure also projects into aperture 25 in plate I3, thus positively aligning contact portion I1. with prongreceiving passage I5.

-As better indicated in Fig. 3, the top of contact portion, I1 is spaced from plate I3 to which, it is secured by means of clip 23. As may be seen in Fig. 2, the contact portions I1 of adjacent i ture said .clip extending through said, aperture contact structures I6' are in close proximity and if these contact portions I1 rested on the plate I 3, the creepage path at this point along plate I3 would be very short. However, by providing an air space between the contact portion I1 and plate I3 the shortest creepage path is between the body portions IB of adjacent contact structures I6' where they are secured to plate I3 by clips 23. This greatly increases the voltageat which the socket will break down. In addition, the space between contagt portion I1 and plate I3 increases the ydistance a contact prong must travel before it engages the contact and insures a proper indexing of' the radio tube before it is inserted in the socket so the hazard of making an improper contact and injuring the tube is reduced. t i

A second plate 21 of insulating material, congruent with plate I3 and provided with a passage coincident with passage I4 and with a second passage I5' coincident with the passage I5, is superimposed upon plate I3 on the side thereof opposite the/ contact structures, to provide an insulated K front for the'socket receptacle, 'and is secured thereto together with supporting structure' II, by a plurality of eyelets 28 or the like. Plates I3 and 21 engage the ends 24 of clip 23, thus preventing the same from slipping or working loose. Eyelets 2B secure the component parts of socket -ture having a contact surface and having an intereceptacle i9 together in assembled relationshipand further secure the socket as a whole to its supporting structure Il.

When a prong on vacuum tube I 2 is inserted into contact portion I1 of the contact structure I6 the contact portion will spread and hinge about the inner edge of clip 23. y'I'his increases both the resiliency of the contact structure and the efficiency of the electrical contact between the prong and the contact structure throughout the life of the socket. As the clip 23 permits the contact structure I1 to expand on a long radius as compared with a contact finger which bends at its base on a short radius, this permits itto return to its original shape after the prong is withdrawn therefrom and so extends the useful life of the socket.

WhileI have illustrated and described one embodiment of my invention, modifications thereof will occur to those skilled in the art. I desire it to be understood, therefore, that my invention is not to be limited to the particular arrangement disclosed and I intend, in the appended claims, to

cover all modications which do not depart from the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a socket of the plug-in type, a sheet of insulating material having a passage therethrough to receive a prong contact, a contact Vstructure de pending'from said sheet said structure including closely adjacent elements having4 opposed surfaces for receiving said prong contact, and a U-shaped clip extending through an aperture in said sheet and embracing said elements to fasten said contact structure to said sheet and to prevent separation of said elements while said surfaces hinge about ,said clip upon receiving a contact prong.

2..In a socket, a sheet of insulating material having a passage therethrough to receive a prong contact and having an aperture, a. contact structure having a contact surface and having an integral tab extending into said aperture, and a U-shaped .clip embracing a portion of said strucand securing said structure to said sheet.

3. In a socket, a sheet of insulating material havinga passage therethrough to receive a prong contact and having an aperture, a contact strucgral tab extending into said aperture, and a LI- shaped clip embracing a portion of said structure said clip passing through said aperture to secure said contact structure to said sheet, said U-shaped clip having bosses to engage opposite edges of said` tab to prevent the rocking of said contact structure relative to said sheet.

4. In a socket, a sheet of insulating material having a passage therethrough to receive a prong contact and havingan aperture therethrough adjacent said passage, a contact structure comprising a metal sheet folded back upon itself, portions of said folds being provided with integral tabs extending into said aperture and other por` tions of said folds being formed to provide opposed contact surfaces, said surfaces being in'` axial alinement with said passage to receive a contact prong, and a U-shaped clip embracing said rstmentioned portions of said folds and said tabs, and extending through said aperture to secure said contact structure to said sheet.

LEONARD w. Coon 

